Height Slice - Direction?

Hello everyone.
I may be wrong, but I have the impression that the result of the Height Slice node is not correct. If you select Horizontal in the Direction parameter, the result corresponds to the slice (the result is perpendicular to the slice), but if you enable Vertical, the result does not change and remains vertical, although in theory it should be perpendicular to the slice. This is confusing. I am not sure if this should be added to the Improvements section, just asking.